The Solar Energy Industries Association (SEIA) already ranks California as the top state in the U.S. when it comes to solar energy.
"Adoption of these standards represents a quantum leap in statewide building standards", said Robert Raymer, technical director for the California Building Industry Association.
Percentage of California electricity from solar: 15.56%. The requirement would only apply to newly constructed homes, not existing ones, although many homeowners are choosing to install solar panels with the help of rebate programs.
The CEC approved the requirement, which still need to backing from the state's Building Standards Commission. It cited Bob Raymer, technical director for the California Building Industry Association (CBIA), as saying that now 15% to 20% of new single-family homes have solar.
The commission estimates they would add an average $10,500 in construction costs for a single-family home but generate about $16,000 in energy savings.
"This is an undeniably historic decision for the state and the U.S. California has always been our nation's biggest solar champion, and its mass adoption of solar has generated huge economic and environmental benefits, including bringing tens of billions of dollars of investment into the state". It requires new homes to have a solar-power system of a minimum 2 to 3 kilowatts, depending mostly on the size of the home. And they include efforts to increase battery storage and increase use of electricity over natural gas. And in California overall, half as many people can afford median priced housing as in the rest of the country.
"That's just going to drive the cost up and make California, once again, not affordable to live", said Assemblyman Brian Dahle, the chamber's Republican leader.
The regulations include exceptions for when solar panels aren't cost-effective or feasible, such as on a home shrouded in shade.
Builders will have the option of adding solar panels to individual homes, or building shared power systems for a group of homes.
Lynn Jurich, co-founder of solar installation company Sunrun, told the New York Times that large market expansions like this make it "very cost effective to do".
The state updates its building codes, including energy efficiency standards, once every three years.
'This is not a radical departure - it's a step in the right direction to reduce our greenhouse gas emissions and improve our air, which for many, many decades California has been doing better and better each time'.